1. Field
The aspects of the disclosed embodiment generally relate to substrate processing tools and, more particularly, to substrate transport apparatus.
2. Brief Description of Related Developments
Generally in substrate processing systems the rotation of arms of transfer robots with multiple arms are linked to one another so as one arm rotates the other arm(s) rotates as well. The end effectors of the transfer robots are generally located in different planes so that a fast swap (e.g. one end effector radially passes over/under the other end effector so that as one substrate is removed from a holding station another substrate is substantially simultaneously placed at the holding station) of substrates to and from holding locations generally occurs using either a Z axis capability of the transfer robot or holding station.
It would be advantageous to decouple the rotation of the arms of substrate transfer robots so that each arm is capable of independent operation.